CN103858248A - dopant injection layer - Google Patents

Abstract

The present invention uses an equipotential source layer for an electronic device, where the equipotential source layer provides charged ions that are preferentially injected into an active layer of the electronic device, such that the injected ions have the same charge sign as the relative bias applied to the equipotential source layer. The source layer may comprise a composite ion dopant implanted layer comprising at least one component having a relatively high diffusion coefficient for ions. The composite ion dopant implanted layer may include metallic conductive particles and an ion supporting matrix. The composite ion dopant implanted layer may also include a continuous metallic conductive network and an ion supporting matrix. The metallic network includes metallic nanowires or conductive nanotubes. The ion supporting matrix includes a conductive polymer.

Description

Translated fromChinese

掺杂剂注入层dopant injection layer

相关申请的交叉引用Cross References to Related Applications

本申请要求于2011年8月2日提交的、题为《掺杂剂注入层（DopantInjection Layers）》的美国临时申请No.61/514,425的优先权，该文的全部内容通过引用纳入本文。This application claims priority to US Provisional Application No. 61/514,425, filed August 2, 2011, entitled "Dopant Injection Layers," which is incorporated herein by reference in its entirety.

发明领域field of invention

本发明涉及使用源层来注入离子，从而改善电子器件的性能。The present invention relates to the use of source layers to implant ions to improve the performance of electronic devices.

背景background

发光电化学电池使用可移动的离子来减小将电子和空穴注入共轭聚合物基发光器件的屏障。美国专利5,682,043（裴（Pei）等）显示了这样的示例性器件。这些器件无需使用低功函的金属作为阴极。这些器件可取得合理的高器件效率和低操作电压。但是，如美国专利No.5,682,043所述，这些器件的开启动力学是相对低的。此外，该器件是固有的电中性的，阳离子和阴离子浓度相等，但是存在相等的阳离子和阴离子浓度不是优化的。Light-emitting electrochemical cells use mobile ions to reduce the barrier for injecting electrons and holes into conjugated polymer-based light-emitting devices. US Patent 5,682,043 (Pei et al.) shows such an exemplary device. These devices do not require the use of low work function metals as cathodes. These devices achieve reasonably high device efficiencies and low operating voltages. However, as described in US Patent No. 5,682,043, the turn-on kinetics of these devices are relatively low. Furthermore, the device is inherently charge neutral with equal cation and anion concentrations, but the presence of equal cation and anion concentrations is not optimal.

使用具有电荷注入增强层的多层器件是改善器件效率和寿命的潜在手段。一些参考文献已经描述了由导电聚合物空穴注入层组成的多层器件，以改善聚合物和小分子有机发光二极管。在常规的聚合物OLED多层器件结构中，聚合物掺杂的共轭有机薄膜已用作空穴注入层。但是，在这些情况下，通过共轭物质(聚3,4-乙撑二氧噻吩–PEDT或PEDOT)形成的导电聚合物被用聚苯乙烯磺酸（PSS）掺杂，但没有特意包含可移动的离子。事实上，掺杂聚合物PSS通常分子量比共轭片段还高，形成固体膜的主体，且与可移动的掺杂剂相比主要是固定的。还感兴趣的是，共轭的PEDOT:PSS的比例通常是相对低的。在PEDOT:PSS的许多应用中，如抗静电涂层、离散的OLED和被动基质OLED，都需要特别的措施来确保电隔离以及因此确保低的横向PEDOT:PSS导电率，所以PSS的含量高于PEDOT含量，且导电率随着PSS含量的增加而降低。常规的OLED器件通常不追求更高导电率级别的PEDOT:PSS。The use of multilayer devices with charge injection enhancing layers is a potential means to improve device efficiency and lifetime. Several references have described multilayer devices composed of conductive polymer hole-injection layers to improve polymer and small molecule organic light-emitting diodes. In conventional polymer OLED multilayer device structures, polymer-doped conjugated organic thin films have been used as hole injection layers. However, in these cases, the conductive polymer formed by conjugated species (poly-3,4-ethylenedioxythiophene – PEDT or PEDOT) was doped with polystyrene sulfonic acid (PSS), without deliberately containing the moving ions. In fact, doped polymer PSSs usually have a higher molecular weight than the conjugated segments, form the bulk of the solid film, and are mainly immobilized compared to mobile dopants. It is also of interest that the ratio of conjugated PEDOT:PSS is generally relatively low. In many applications of PEDOT:PSS, such as antistatic coatings, discrete OLEDs and passive matrix OLEDs, special measures are required to ensure electrical isolation and thus low lateral PEDOT:PSS conductivity, so the content of PSS is higher than PEDOT content, and the electrical conductivity decreases with the increase of PSS content. Conventional OLED devices generally do not pursue higher conductivity levels of PEDOT:PSS.

PEDOT:PSS更少用于发光电化学电池（也称为LEC）。LEC操作原理包括在发光层中使用可移动的离子掺杂剂，来在阳极产生掺杂的界面。这减少了对空穴注入增强层如PEDOT:PSS的需求，因为LEC掺杂的界面已经用作该目的。注意到掺杂的PEDOT:PSS层的确会吸收从该器件的活性层通过这些层的光传播。这降低了外部效率，并因此使得典型的PEDOT:PSS是不利的，除非出于其它必要的原因。基于公知常识和对LEC模型的简单考虑，本领域技术人员将假定在LEC中包含共轭聚合物注入层不是有利的，且高的掺杂水平也不是有利的，因为会带来高的吸收损失和漏电流。此外，在常规OLED中，存在离子尤其是可能漂移或扩散进入该器件的活性层的可移动的离子，通常被认为是不利的，因为这些杂质会导致效率损失和器件退化。PEDOT:PSS is less commonly used in light-emitting electrochemical cells (also known as LECs). The principle of operation of the LEC involves the use of mobile ionic dopants in the light-emitting layer to create a doped interface at the anode. This reduces the need for a hole-injection enhancing layer such as PEDOT:PSS, since the LEC-doped interface is already used for this purpose. Note that the doped PEDOT:PSS layers do absorb light propagating from the active layers of the device through these layers. This reduces external efficiency and thus makes typical PEDOT:PSS unfavorable unless for other necessary reasons. Based on common knowledge and simple consideration of the LEC model, one skilled in the art will assume that it is not advantageous to include a conjugated polymer injection layer in the LEC, nor is a high doping level because of the high absorption losses and leakage current. Furthermore, in conventional OLEDs, the presence of ions, especially mobile ions that may drift or diffuse into the active layers of the device, is generally considered to be unfavorable, since these impurities lead to loss of efficiency and degradation of the device.

最近，已经为有机发光器件结构提出了另一种掺杂多层。在这种情况下，提出的多层固有的漂移迁移率控制在类似LEC器件中的掺杂剂的流动，从而创建有利的效果。在极端情况下，甚至通过共价键固定掺杂剂抗衡离子。此外，题为《具有离子受体层的聚合物发光二极管（Polymer light-emitting diodewith an ion receptor layer）》的美国专利No.7,868,537（梅捷（Meijer）等）已经提出使用离子受体来固定从抗衡离子层供应的离子。美国专利No.7,868,537还包括了一种器件的示例和描述，其中使用PEDOT:PSS层作为可移动的阳离子的来源，该阳离子可在正向偏压下流向阳离子受体。。但是，美国专利No.7,868,537将阳离子来源归功为PEDOT:PSS中的Na+，而Na+并没有特意的以显著数量存在，并通常认为是造成器件中偏压应力退化的原因。此外，美国专利No.7,868,537将阴离子的固定归功于它的聚合物性质。Recently, another doped multilayer has been proposed for organic light-emitting device structures. In this case, the intrinsic drift mobility of the proposed multilayer controls the flow of dopants in LEC-like devices, thus creating a favorable effect. In extreme cases, dopant counterions are even immobilized by covalent bonds. In addition, U.S. Patent No. 7,868,537 (Meijer et al.) entitled "Polymer light-emitting diode with an ion receptor layer" has proposed the use of ion receptors to immobilize light-emitting diodes from Ions supplied by the counterion layer. US Patent No. 7,868,537 also includes an example and description of a device using a PEDOT:PSS layer as a source of mobile cations that can flow towards a cation receptor under forward bias. . However, US Patent No. 7,868,537 attributes the source of cations to Na+ in PEDOT:PSS, which is not intentionally present in significant amounts and is generally considered to be responsible for bias stress degradation in devices. Furthermore, US Patent No. 7,868,537 attributes the immobilization of anions to its polymeric nature.

美国专利No.7,868,537没有描述下述事实：PEDOT:PSS具有金属性性质，其中零电场将抑制PEDOT:PSS内的离子运动，且当PEDOT:PSS上有正向偏压时，在PEDOT:PSS界面将优先的只注入阳离子，而与阴离子尺寸无关。包括具有高载流子浓度的导电注入层（如PEDOT:PSS），阳离子和阴离子的再分布将由扩散驱动。在正向偏压（正的PEDOT:PSS）中，可移动的阳离子的注入会很快消耗活性层界面处PEDOT:PSS中的区域。在PEDOT:PSS整体上并没有分布显著数量的、可扩散到界面区域并维持阳离子供应的可移动的离子，将会抑制该掺杂剂注入效应。如下文所描述，这些掺杂剂必须作为特意的、外在掺杂剂来引入。U.S. Patent No. 7,868,537 does not describe the fact that PEDOT:PSS has metallic properties, wherein zero electric field will suppress ion motion inside PEDOT:PSS, and when there is a forward bias on PEDOT:PSS, the PEDOT:PSS interface Only cations will be preferentially implanted regardless of anion size. Including a conductive injection layer with high carrier concentration (such as PEDOT:PSS), the redistribution of cations and anions will be driven by diffusion. In forward bias (positive PEDOT:PSS), the implantation of mobile cations quickly consumes the area in PEDOT:PSS at the active layer interface. The absence of a significant distribution of mobile ions throughout the PEDOT:PSS that can diffuse into the interfacial region and maintain a supply of cations would suppress this dopant implantation effect. These dopants must be introduced as deliberate, extrinsic dopants, as described below.

概述overview

本发明使用了用于电子器件的等电位源层，其中该等电位源层提供优先注入该电子器件的活性层的带电荷离子，从而该被注入的离子的电荷具有与应用到该等电位源层的相对偏压的符号相同的符号。该源层可包括复合材料离子掺杂剂注入层，其包括至少一种对离子具有相对高的扩散系数的组分。该复合材料离子掺杂剂注入层可包括金属性导电颗粒和离子支撑基质。该复合材料离子掺杂剂注入层还可包括连续的金属性导电网络和离子支撑基质。该金属性网络包括金属性纳米线或导电纳米管。该离子支撑基质包括导电聚合物。The present invention uses an equipotential source layer for an electronic device, wherein the equipotential source layer provides charged ions that are preferentially injected into the active layer of the electronic device so that the charge of the implanted ions has a The signs of the relative bias of the layers are the same. The source layer may include a composite ion dopant implantation layer including at least one component having a relatively high diffusion coefficient for ions. The composite ion dopant implantation layer may include metallic conductive particles and an ion-supporting matrix. The composite ion dopant implanted layer may also include a continuous metallically conductive network and an ion-supporting matrix. The metallic network includes metallic nanowires or conductive nanotubes. The ionically supporting matrix includes a conductive polymer.

在一种实施方式中，该器件包括透明阳极、与该透明阳极接触的导电聚合物层，以及邻近该活性层的额外的可移动的离子掺杂剂。In one embodiment, the device includes a transparent anode, a conductive polymer layer in contact with the transparent anode, and an additional mobile ion dopant adjacent to the active layer.

在另一种实施方式中，该器件包括透明阴极和掺杂的阳极，所述掺杂的阳极是金属性元件的连续导电网络和离子支撑基质形成的复合材料。In another embodiment, the device includes a transparent cathode and a doped anode that is a composite of a continuous conductive network of metallic elements and an ion-supporting matrix.

通过阅读发明详述和附图，本发明的这些其它实施方式对本领域技术人员来说是显而易见的。These other embodiments of the invention will be apparent to those skilled in the art from reading the detailed description and drawings.

附图简要说明Brief description of the drawings

图1A-1B显示了来自印刷器件的恒流测试的初始“开启”数据，表明了与未掺杂的阴极对照相比，用某“含盐”Ag制剂掺杂的阴极对恒流器件的发光度和电压随时间的影响。Figures 1A-1B show initial "turn-on" data from galvanostatic testing of printed devices, demonstrating the luminescence of a galvanostatic device with a cathode doped with a "salt-containing" Ag formulation compared to an undoped cathode control temperature and voltage over time.

图2显示了对照（具有使用标准Ag制剂的阴极的未掺杂器件）和使用2种不同“含盐”Ag制剂掺杂阴极的掺杂的阴极器件，在制造完即刻得到的EL图像。所有的器件都包括丝网印刷的LEP。顶部的一排图像来自使用标准Ag制剂10-243-1Ag的2个器件。中部的一排图像来自使用“含盐”Ag制剂10-243-1-ion1的2个器件。如下文所进一步描述，底部的一排图像来自使用掺杂程度为10-243-1-ion1两倍的“含盐”Ag制剂10-243-1-ion2的2个器件。从图中明显可知，与对照相比，掺杂的器件的效率是差的，掺杂程度更高的阴极效率更差。Figure 2 shows EL images obtained immediately after fabrication for a control (undoped device with a cathode using a standard Ag formulation) and a doped cathode device doped with cathodes using 2 different "salt-containing" Ag formulations. All devices include screen printed LEP. The top row of images is from 2 devices using the standard Ag formulation 10-243-1Ag. The middle row of images is from 2 devices using the "saline" Ag formulation 10-243-1-ion1. As described further below, the bottom row of images is from 2 devices using a "saline" Ag formulation 10-243-1-ion2 doped twice as much as 10-243-1-ion1. It is evident from the figure that the efficiency of the doped device is poor compared to the control, with the more highly doped cathode being even less efficient.

图3用图表显示了实验数据组，每一数据组都相对于对照数据进行了标准化和指数拟合。在拟合曲线中的最大值显示了～17重量%BMP/PEDOT:PSS固体的掺杂水平。Figure 3 graphically shows the experimental data sets, each normalized and exponentially fitted relative to the control data. The maximum in the fitted curve shows a doping level of -17 wt% BMP/PEDOT:PSS solids.

如下文所进一步描述，图4A-C显示了均匀的、可移动的离子掺杂的发光器件（LEC类）在不同时间点的掺杂浓度（顶部一排的图表）和离子分布（底部一排的器件示意图），该发光器件的阴离子和阳离子迁移率相等。在均匀掺杂的情况下，假定所有离子的扩散系数相等。在器件示意图中，一个电极显示成光滑的ITO（元件402），且另一个电极404显示为颗粒状的。但是，本领域技术人员应理解，在本发明的范围内，该电极的具体材料、性质和构造可修改以适合所需的情况。在2个电极之间的发光材料406具有正离子和负离子。As described further below, Figures 4A–C show the doping concentration (top row of graphs) and ion distribution (bottom row Schematic of the device), the anion and cation mobilities of the light-emitting device are equal. In the case of uniform doping, the diffusion coefficients of all ions are assumed to be equal. In the device schematic, one electrode is shown as smooth ITO (element 402 ), and theother electrode 404 is shown as grainy. However, it will be appreciated by those skilled in the art that the specific materials, properties and configuration of the electrodes may be modified to suit the desired situation within the scope of the present invention. Theluminescent material 406 between the two electrodes has positive ions and negative ions.

图4A-C显示了预期的掺杂剂分布随时间的发展。具体来说，从左到右有3种情况：偏压之前(图4A)，偏压之初(图4B)，以及在偏压下经过显著时间后(图4C)。注意到因为掺杂剂浸析进入阴极，在阴极附近的掺杂会降低。Figures 4A-C show the expected dopant profile development over time. Specifically, there are 3 cases from left to right: before bias (Fig. 4A), at the beginning of bias (Fig. 4B), and after a significant time under bias (Fig. 4C). Note that doping near the cathode is reduced due to leaching of dopants into the cathode.

图5A-5C显示了在邻近阴极处有更高掺杂浓度层且在邻近阳极处有更低掺杂浓度层的器件的离子分布，且阴离子和阳离子迁移率相同，表明掺杂剂分布预期的随时间发展。在一种实施方式中，邻近阳极的高度掺杂层的掺杂程度是邻近阴极的相对低度掺杂层的2倍。在阴极和阳极之间，可有多个(2个或以上)离散的层，每一层都具有自己的掺杂浓度水平。也可存在梯度浓度差异。具体来说，图5中从左到右有3种情况：偏压之前(图5A)，偏压之初(图5B)，以及在偏压下经过显著时间后(图5C)。注意到相对于偏压之前的离子，该器件初始时是电中性的。与图4A-4C的情况类似，假定所有的离子的扩散系数相同。Figures 5A-5C show the ion distribution of a device with a layer of higher doping concentration adjacent to the cathode and a layer of lower doping concentration adjacent to the anode, with the same anion and cation mobilities, indicating the expected dopant distribution. Evolve over time. In one embodiment, the highly doped layer adjacent to the anode is twice as doped as the relatively lightly doped layer adjacent to the cathode. Between the cathode and anode, there may be multiple (2 or more) discrete layers, each with its own doping concentration level. There may also be gradient concentration differences. Specifically, there are 3 cases from left to right in Figure 5: before bias (Figure 5A), at the beginning of bias (Figure 5B), and after a significant amount of time under bias (Figure 5C). Note that the device is initially charge neutral with respect to the ions before biasing. Similar to the case of FIGS. 4A-4C , it is assumed that all ions have the same diffusion coefficient.

图6A-5C显示了具有掺杂的阴极层和均匀掺杂（沉积的）活性层的器件的离子分布，且阴离子和阳离子迁移率相同，表明掺杂剂分布预期的随时间发展。具体来说，从左到右有3种情况：偏压之前(图6A)，偏压之初(图6B)，以及在偏压下经过显著时间后(图6C)。靠近阴极处掺杂的少量增加，预计是因为来自掺杂的阴极的扩散和相互混合。与图4A-4C和5A-5C的情况类似，假定所有的离子的扩散系数相同。Figures 6A-5C show the ion distribution of a device with a doped cathode layer and a uniformly doped (deposited) active layer, with the same anion and cation mobilities, indicating the expected evolution of the dopant distribution over time. Specifically, there are 3 cases from left to right: before bias (Fig. 6A), at the beginning of bias (Fig. 6B), and after a significant time under bias (Fig. 6C). The small increase in doping near the cathode is expected to be from diffusion and intermixing of doped cathodes. Similar to the case of Figures 4A-4C and 5A-5C, all ions are assumed to have the same diffusion coefficient.

图7A-5C显示了具有掺杂的导电阳极掺杂剂注入层和均匀掺杂（沉积的）活性层的器件的离子分布，且阴离子和阳离子迁移率相同，表明掺杂剂分布预期的随时间发展。具体来说，从左到右有3种情况：偏压之前(图7A)，偏压之初(图7B)，以及在偏压下经过显著时间后(图7C)。靠近阳极处掺杂的少量增加，预计是因为来自掺杂层的扩散和相互混合。随着时间的推移，在该器件的活性层中创建了高阳离子浓度，这改善了电子注入限制器件的空穴平衡并最小化了过量的阴离子淬灭。与图4A-4C、5A-5C和6A-6C的情况类似，假定所有的离子的扩散系数相同。Figures 7A-5C show the ion distribution of a device with a doped conductive anode dopant-injection layer and a uniformly doped (deposited) active layer with the same anion and cation mobilities, indicating the expected dopant distribution over time. develop. Specifically, there are 3 cases from left to right: before bias (Fig. 7A), at the beginning of bias (Fig. 7B), and after a significant time under bias (Fig. 7C). The small increase in doping near the anode is expected to be due to diffusion and intermixing from doped layers. Over time, a high cation concentration is created in the active layer of the device, which improves the electron-injection-limited device hole balance and minimizes excess anion quenching. Similar to the case of Figures 4A-4C, 5A-5C and 6A-6C, all ions are assumed to have the same diffusion coefficient.

发明详述Detailed description of the invention

对于一些活性层半导体，优先增强来自例如在靠近阴极界面处具有高阳离子浓度的阴极的注入，且限制阴离子浓度是更加有利的。这可优先的增强电子注入，且创建更好的电子/空穴平衡，来增加器件的量子效率，同时最小化过量掺杂剂离子的淬灭或其它降低寿命的影响如不必要的高阴离子浓度。For some active-layer semiconductors, it is more advantageous to preferentially enhance implantation from a cathode with a high cation concentration, eg, near the cathode interface, and to limit the anion concentration. This can preferentially enhance electron injection and create a better electron/hole balance to increase the quantum efficiency of the device while minimizing quenching of excess dopant ions or other lifetime-reducing effects such as unnecessarily high anion concentrations .

本发明的实施方式表明掺杂基本没有电场的源层，制备了用于包含进入有机电子器件的高度有效的单电子注入层。源层可以是非半导体的、金属性的或半金属性的。源层包括导电和非导电元件的复合网络，且具有实际上为零的内部电场。Embodiments of the present invention demonstrate that doping a source layer with substantially no electric field produces highly efficient single electron injection layers for inclusion into organic electronic devices. The source layer can be non-semiconducting, metallic or semi-metallic. The source layer comprises a composite network of conductive and non-conductive elements and has a virtually zero internal electric field.

这些零电场、单电子注入层可包括共轭聚合物导体（如PEDOT:PSS)和额外的小的、可移动的离子性掺杂剂，或者它们可包括异质金属/有机复合电极（如具有有机粘合剂的印刷金属颗粒层，其中粘合剂可具有不同功能，包括，但不限于，离子复合、电解或离子存储功能中的一种或更多种）。本发明使用的一种实施例发光聚合物制剂基于默克（Merck）/克分（Covion）的超黄聚苯亚乙烯(polyphenylene vinylene)，它是一种有机半导体，对空穴注入的屏障相对低于对电子注入的屏障。对于该器件，最高占据分子轨道(HOMO)=5.2eV，最低空分子轨道(LUMO)=2.8eV。应指出，感兴趣的稳定电极金属如Al或Ag的功函为～4.3eV，且依赖于处理条件，ITO的功函范围是4.3eV-5.2eV。典型的发光器件制备包括氧等离子体或UV臭氧处理ITO表面（本发明中的示例器件使用UV臭氧处理），预计导致表面电势在5-5.2eV功函范围。在这种情况下，对从ITO阳极将空穴注入SY-基活性层只有很少或没有屏障，但对从所需的稳定金属如Al或Ag的用于电子注入SY LUMO能级的空穴注入（(～1.5eV)）却有实质性屏障。但是，也可有这样的情况，如高LUMO和HOMO能级活性层半导体，其中空穴注入是受限制的。These zero-field, single-electron injection layers can include conjugated polymer conductors (such as PEDOT:PSS) and additional small, mobile ionic dopants, or they can include heterogeneous metal/organic hybrid electrodes (such as with A printed metal particle layer of an organic binder, where the binder may have different functions including, but not limited to, one or more of ion recombination, electrolysis, or ion storage functions). One example light-emitting polymer formulation used in the present invention is based on Merck/Covion's ultra-yellow polyphenylene vinylene, an organic semiconductor with a relatively high barrier to hole injection. below the barrier to electron injection. For this device, the highest occupied molecular orbital (HOMO) = 5.2eV and the lowest unoccupied molecular orbital (LUMO) = 2.8eV. It should be noted that stable electrode metals of interest such as Al or Ag have a work function of ~4.3 eV, and that ITO ranges from 4.3 eV to 5.2 eV depending on the processing conditions. Typical light-emitting device fabrication includes oxygen plasma or UV ozone treatment of the ITO surface (the example devices in this invention use UV ozone treatment), which are expected to result in surface potentials in the 5-5.2 eV work function range. In this case, there is little or no barrier to hole injection from the ITO anode into the SY-based active layer, but to holes from the desired stable metal such as Al or Ag for electron injection into the SY LUMO level. Injection ((~1.5eV)) has a substantial barrier. However, there may also be cases, such as high LUMO and HOMO level active layer semiconductors, where hole injection is limited.

一般有机发光器件的外部量子效率可用下式描述：The external quantum efficiency of a general organic light-emitting device can be described by the following formula:

η_ext=η_Phη_int=η_Phγφη_exη_ext =η_Ph η_int =η_Ph γφη_ex

式中In the formula

η_ext=外部效率η_ext = external efficiency

η_ph=光子耦合输出（out-coupling）效率η_ph = photon out-coupling efficiency

η_int=内部效率η_int = internal efficiency

γ=电子和空穴的比例，通常≤1。因为不平衡，所以会有能量损失。γ = ratio of electrons to holes, usually ≤1. Because of the imbalance, there will be energy loss.

φ=发射器的发光复合量子效率。φ = luminescent recombination quantum efficiency of the emitter.

η_ex=基于自旋统计的发光激发分数。η_ex = luminescent excitation fraction based on spin statistics.

从上式可知，电子/空穴比例（也称为“电子空穴平衡”）是一个关键参数。这个参数受到器件结构和材料的2种情况的影响：电荷注入和电荷传输。当对电荷注入的屏障较低时，载流子流通，因此电子/空穴平衡由空间电荷限制传输效应主导。这些空间电荷效应依赖于传输距离和载流子迁移率。但是，在本文感兴趣的高功函、稳定的电极材料的情况下，通常电荷注入是更重要的因素。在具有透明、高功函阳极和相对稳定（(>4eV在这种情况下）金属阴极的SY-基发光器件中，电子注入才是器件效率的主导因素。在这种情况下，使用外在掺杂的、金属性导电聚合物、PEDOT:PSS作为阳离子注入源是有利的。但是，对于具有透明阴极器件的相反的构造中，可在阳极使用不透明掺杂剂注入层，例如能将掺杂剂接受进入基质的金属颗粒复合材料。此外，如上所述，空穴注入受限的器件将受益于阴极层掺杂，不管这种掺杂来自掺杂的均匀导体材料如掺杂的共轭聚合物或者来自异质金属复合材料。金属复合材料是特别感兴趣的，因为它们易于通过丝网印刷、孔板印刷、柔版印刷、凹版印刷、喷墨印刷、气溶胶喷涂、分配等来印刷。From the above equation, it can be seen that the electron/hole ratio (also known as "electron-hole balance") is a key parameter. This parameter is affected by 2 conditions of the device structure and materials: charge injection and charge transport. When the barrier to charge injection is low, carriers flow and thus the electron/hole balance is dominated by space charge-limited transport effects. These space charge effects are dependent on transport distance and carrier mobility. However, in the case of the high work function, stable electrode materials of interest here, charge injection is generally the more important factor. In SY-based light-emitting devices with a transparent, high work function anode and a relatively stable (>4eV in this case) metal cathode, electron injection is the dominant factor in device efficiency. In this case, using an extrinsic Doped, metallic conductive polymers, PEDOT:PSS are advantageous as a source of cation implantation. However, for the opposite configuration with a transparent cathode device, an opaque dopant implant layer can be used at the anode, e.g. agent accepts metal particle composites into the matrix. Furthermore, as noted above, hole-injection-limited devices would benefit from cathodic layer doping, regardless of whether this doping comes from doped homogeneous conductor materials such as doped conjugated polymeric or from heterogeneous metal composites. Metal composites are of particular interest because of their ease of printing by screen printing, stencil printing, flexo printing, gravure printing, inkjet printing, aerosol spraying, dispensing, and the like.

本发明涉及掺杂注入层，它与“LEP多层”应用中的多层是不同的。本发明的构思是离子通过邻近的导电或非半导体层注入器件的活性区域，由此可注入单一电荷的离子而无需抗衡离子（通过该层与邻近的电极接触产生的电势，将抗衡离子固定在导电层中）。这使得在应用的偏压稳定状态，能将更高浓度的阳离子注入器件中，可优先的增强阴极注入，阴极注入常常是OLED器件的限制因素。对于高功函印刷电极器件，这特别有效。在这些情况下，增加的阴极注入可通过更好的电子/空穴平衡导致更高的EQE，以及导致更长的器件寿命。离子的额外供应还可通过置换流入阴极的、丢失的掺杂剂来降低在寿命中的电压上升。The present invention relates to doped implanted layers, which are different from the multilayers used in "LEP multilayer" applications. The idea of the present invention is that ions are implanted into the active region of the device through adjacent conducting or non-semiconducting layers, whereby singly charged ions can be implanted without the need for counter ions (which are anchored at the in the conductive layer). This enables a higher concentration of cations to be injected into the device at steady state applied bias, preferentially enhancing cathodic injection, which is often the limiting factor in OLED devices. This is especially effective for high work function printed electrode devices. In these cases, increased cathode injection can lead to higher EQE through better electron/hole balance, as well as to longer device lifetime. The extra supply of ions can also reduce the voltage rise over lifetime by displacing lost dopants flowing into the cathode.

因为在导电或导电复合材料层中实际为零的电场，抑制了与电极电荷类似的离子的运动，而它的抗衡离子在偏压下处于稳定状态，可以以更高的、无补偿的水平注入该器件的半导体活性层。例如，用如中性有机离子液体的盐掺杂的导电层与器件的阳极有电接触时，将会优先的将阳离子从该导电层界面注入活性层，同时抑制阴离子注入。这将会创建相对高阳离子浓度，当更高数量的阳离子可增加来自阴极的电子注入并因此增加电子注入受限器件的量子效率时，这变得特别令人感兴趣，且不会相应的增加阴离子增强的空穴注入。这不依赖于离子的迁移率，因此与工业已知的有本质上的不同。Because of the practically zero electric field in the conductive or conductive composite layer, which inhibits the movement of ions similar to the electrode charge, its counterion is stable under bias and can be injected at higher, uncompensated levels The semiconductor active layer of the device. For example, doping a conductive layer with a salt such as a neutral organic ionic liquid in electrical contact with the anode of the device will preferentially inject cations into the active layer from the interface of the conductive layer while suppressing anion injection. This would create a relatively high cation concentration, which becomes of particular interest as higher numbers of cations can increase electron injection from the cathode and thus increase the quantum efficiency of electron injection limited devices without a corresponding increase in Anion-enhanced hole injection. This does not depend on the mobility of the ions and is therefore fundamentally different from what is known in the industry.

为了测试本发明提出的实施方式，因为易于制备掺杂的印刷阴极浆料和可购买标准活性层墨水，初始时可非常方便的来测试反向假设，即在SY基器件的导电阴极中包括掺杂剂会降低电子注入受限器件的效率，因为将掺杂剂添加到阴极中会导致将更高分数的阴离子注入该器件，这会负面影响电子/空穴平衡且引入额外的淬灭位点。在阴极掺杂的情况下，掺杂剂实际上是溶于粘合剂中，因为掺杂剂本身不溶于组成印刷复合材料导电网络的本体金属颗粒中。In order to test the proposed embodiment of the present invention, because of the ease of preparation of doped printed cathode pastes and the availability of standard active layer inks, it is very convenient initially to test the converse hypothesis that the conductive cathodes of SY-based devices include doped Dopants reduce the efficiency of electron-injection-limited devices because adding dopants to the cathode results in a higher fraction of anions being injected into the device, which negatively affects the electron/hole balance and introduces additional quenching sites . In the case of cathodic doping, the dopant is actually soluble in the binder, since the dopant itself is insoluble in the bulk metal particles that make up the conductive network of the printed composite.

尝试了一个实验，其中器件结构包括在PET基底上的图案化ITO层，且该ITO层上凹印了～500纳米厚度的掺杂的LEP活性层(SY LEP+PEO+离子性掺杂剂)，其基础配方如下所示：An experiment was attempted in which the device structure consisted of a patterned ITO layer on a PET substrate with a doped LEP active layer (SY LEP + PEO + ionic dopant) debossed ~500 nm thick, Its basic formula is as follows:

表1掺杂的发光聚合物活性层制剂Table 1 Doped light-emitting polymer active layer formulation

·‘4ma’=4－甲基苯甲醚溶剂·'4ma'=4-methylanisole solvent

·‘SY71”指默克超黄发光聚合物的具体批料· ‘SY71’ refers to the specific batch of Merck’s Super Yellow Light Emitting Polymer

·‘PY1A’指预先制备的丁基甲基吡咯烷三氟甲磺酸硫酰亚胺（ionic liquid butyl methyl pyrolodinium triflate sulfimide）(BMPYRTfSi)和四丁基铵三氟甲磺酸硫酰亚胺(TBATFSi)的离子液体混合物'PY1A' refers to pre-prepared ionic liquid butyl methyl pyrolodinium triflate sulfimide (BMPYRTfSi) and tetrabutylammonium triflate sulfimide (TBATFSi) ionic liquid mixture

·‘DBP534’是聚环氧乙烷、聚环氧丙烷、和聚二甲基硅氧烷三嵌段共聚物，具有表面活性剂和电解质功能，可从格乐斯特（Gelest）购买'DBP534' is a polyethylene oxide, polypropylene oxide, and polydimethylsiloxane triblock copolymer with surfactant and electrolyte functionality, commercially available from Gelest

·DMS-T00是低分子量的硅氧烷表面活性剂，在器件制造过程中大量挥发，可从格乐斯特（Gelest）购买DMS-T00 is a low molecular weight siloxane surfactant that is highly volatile during device fabrication and can be purchased from Gelest

在该活性发光层上面印刷和干燥用于丝网印刷的掺杂的阴极墨水（制剂10-243-1-ion1），其中掺杂剂与有机粘合剂比例为～3.3%的，以形成3-4微米厚的顶部电极并完成该器件堆叠件。同时，使用对照阴极混合物10-243-1，制造了具有厚度大致相同的一组平行器件。作为公开的非限制性例子，一种掺杂的阴极墨水制剂（称为10-243-1-ion1），具有以下性能特征：A doped cathodic ink for screen printing (Formulation 10-243-1-ion1) with a dopant to organic binder ratio of ~3.3% was printed and dried on top of the active emissive layer to form 3 - 4 micron thick top electrode and complete the device stack. Simultaneously, using the control cathode mix 10-243-1, a set of parallel devices having approximately the same thickness was fabricated. As a disclosed non-limiting example, a doped cathode ink formulation (designated 10-243-1-ion1) having the following performance characteristics:

·100g Ag Lot10-243-1(AG752(基于非薄片Ag颗粒的阿德威津公司（Add-Vision）/导电复合物公司（Conductive Compounds）Ag浆料配方，含Ag～70%Ag，含基质固体～8%，还含平衡溶剂和挥发性物质))100g Ag Lot10-243-1 (AG752 (Add-Vision/Conductive Compounds) Ag paste formula based on non-flake Ag particles, containing Ag ~ 70% Ag, containing matrix Solid ~ 8%, also contains equilibrium solvent and volatile matter))

·200毫克γ-丁内酯溶剂· 200 mg gamma-butyrolactone solvent

·200毫克BMPYRTFSI(丁基甲基吡咯烷三氟甲磺酸硫酰亚胺离子液体)200 mg BMPYRTFSI (butylmethylpyrrolidine trifluoromethanesulfonylsulfimide ionic liquid)

·70毫克TBATFSI(四丁基铵三氟甲磺酸硫酰亚胺)70 mg of TBATFSI (tetrabutylammonium trifluoromethanesulfonyl sulfimide)

该制剂使用相对于Ag粘合剂～3.3重量%的离子浓度。标准Ag制剂10-243-1的所测粘度是193,750cP，具体“含盐”Ag制剂10-243-1-ion1的所测粘度是197,500cP。The formulation used an ion concentration of -3.3 wt% relative to the Ag binder. The measured viscosity of the standard Ag formulation 10-243-1 was 193,750 cP and the measured viscosity of the specific "salt" Ag formulation 10-243-1-ion1 was 197,500 cP.

在氮气中，对具有掺杂的阴极“含盐”Ag制剂的器件、由对照未掺杂的阴极制剂（即标准Ag制剂）制成的器件进行在4mA/cm2下的恒流偏压测试。来自这些器件的示例性数据见图1A-1B。在图1A-1B中，使用了凹版印刷的LEP。图1A显示了来自使用了标准Ag制剂的对照器件的结果，其需要4.3秒的时间来升高到15V。图1B显示了来自使用了“含盐”Ag制剂的器件的结果，其需要小于0.29秒的时间来升高到15V。驱动电流是4.0mA。清楚的显示了在该器件的初始开启阶段，相对于对照器件，掺杂的阴极器件的操作电压和效率同时下降。这种行为与邻近器件阳极区域增强的掺杂是一致的，该增强的掺杂还增加了空穴电流注入，由此降低了提供恒流所需的电压，但降低了器件的效率，因为不利的将电子/空穴平衡进一步降至低供应量（空穴主导的）。表2总结了测试数据，包括阴极的寿命（发光度为一半的时间），最大效率和电压瞬态特性和粘度。粘度数据表明墨水粘度现在发生了实质上的变化（掺杂剂的正向增加在测量的误差范围内）。Constant current bias testing at 4 mA/cm2 was performed on devices with a doped cathode "saline" Ag formulation, devices made from a control undoped cathode formulation (ie, a standard Ag formulation) in nitrogen. Exemplary data from these devices are shown in Figures 1A-1B. In Figures 1A-1B, a gravure printed LEP was used. Figure 1A shows the results from a control device using a standard Ag formulation, which required 4.3 seconds to ramp up to 15V. Figure IB shows the results from a device using a "saline" Ag formulation, which required less than 0.29 seconds to ramp up to 15V. The driving current is 4.0mA. It is clearly shown that during the initial turn-on phase of the device, both the operating voltage and the efficiency of the doped cathode device decrease relative to the control device. This behavior is consistent with enhanced doping in the anode region adjacent to the device, which also increases hole current injection, thereby reducing the voltage required to provide a constant current, but reducing the efficiency of the device because of the adverse The electron/hole balance is further reduced to low supply (hole-dominated). Table 2 summarizes the test data, including cathode lifetime (time at which luminosity is half), maximum efficiency and voltage transient characteristics and viscosity. The viscosity data shows that the ink viscosity has now changed substantially (positive increase in dopant is within the error of the measurement).

表2一种示例性掺杂的阴极器件的实验数据总结Table 2 Summary of Experimental Data for an Exemplary Doped Cathode Device

在该表中，10-243-1指标准Ag制剂，而10-243-1-ion1指具体的“含盐”Ag制剂。In this table, 10-243-1 refers to the standard Ag formulation, while 10-243-1-ion1 refers to the specific "salt-containing" Ag formulation.

基于印刷的、掺杂的LEP器件上阴极掺杂的初始的显著负面的结果，进行了第2轮实验，降低了阴极中的掺杂水平，因为那些器件可能被由高度掺杂的阴极引入的大总量掺杂剂过度掺杂。这包括将第一掺杂的阴极制剂10-243-ion1的阴极掺杂浓度降低2X(10-243-ion2)和10X(10-243-ion3)。Based on the initial significantly negative results of cathode doping on printed, doped LEP devices, a second round of experiments was performed, reducing the level of doping in the cathode, since those devices could be induced by highly doped cathodes. A large amount of dopant is overdoped. This included reducing the cathode doping concentration of the first doped cathode formulation 10-243-ion1 by 2X (10-243-ion2) and 10X (10-243-ion3).

实验数据表明相对于第一掺杂阴极实验(使用10-243-ion1)，降低阴极掺杂水平的确改善了器件性能。但是，观察到的效率和寿命仍然比未掺杂的阴极对照更差，且用于更轻度掺杂的阴极的电压介于具有更高度掺杂的阴极的器件和具有未掺杂的阴极的对照器件之间。进一步将阴极掺杂浓度降低10X，至～0.3%掺杂剂/粘合剂，相对于对照（未显示），仍然显示了对器件的负面影响。在偏压的、掺杂的阴极器件中离子分布的一般化图表见图5A-5C。这些结果支持以下假设：The experimental data indicate that reducing the cathode doping level does improve device performance relative to the first doped cathode experiment (using 10-243-ion1). However, the observed efficiency and lifetime were still worse than the undoped cathode control, and the voltage for the more lightly doped cathode was between that of the device with the more highly doped cathode and that with the undoped cathode. between devices. A further reduction of the cathode doping concentration by 1OX, to ~0.3% dopant/binder, relative to the control (not shown), still showed a negative impact on the device. Generalized diagrams of ion distribution in biased, doped cathode devices are shown in Figures 5A-5C. These results support the following hypothesis:

(a)更高浓度的阴离子降低了阳极/LEP注入的屏障，且增加了空穴注入该器件。这在恒流操作下导致更低的偏压，因为在更低的应用电压下可有大的空穴电流。因为很多OLED器件已经是缺电子的，特别是具有相对于活性层HOMO能级（价带）的良好功函阳极的印刷阴极器件，在具有相对更高空穴电流的恒流驱动下，会促使电子/空穴平衡更加的富空穴，因此降低了效率和发光度寿命。(a) A higher concentration of anions lowers the barrier to anode/LEP injection and increases hole injection into the device. This results in a lower bias voltage under constant current operation, since large hole currents are available at lower applied voltages. Because many OLED devices are already electron deficient, especially printed cathode devices with a good work function anode relative to the active layer HOMO level (valence band), driven by a constant current with a relatively higher hole current, will promote electron The /hole balance is more hole-rich, thus reducing efficiency and luminosity lifetime.

(b)更有利的情况是制备阳离子注入的阳极层，这将升高阳离子浓度，促使电子/空穴比例到更加平衡的情况，由此增加EQE和寿命，同时降低电压。(b) A more favorable case would be to prepare a cation-implanted anode layer, which would increase the cation concentration and drive the electron/hole ratio to a more balanced situation, thereby increasing EQE and lifetime while reducing voltage.

通过制造基于参考文献S基兹梅亚（Kirchmeyer,S.）、K路透耳（Reuter,K）等发表于《化学材料期刊（J.Mater.Chem.）》,2005,15,2077-2088,的《聚3，4-乙撑二氧噻吩的科学重要性、性质和应用（Scientific importance,properties and growing applications ofpoly(3,4-ethylenedioxythiophene)）》（称为“基兹梅亚参考文献”）所述的制剂的器件来测试这些假设，但还包括了邻近阳极的离子液体掺杂的PEDOT层。选择市售的克里维斯（Clevios）PEDOT:PSS制剂作为合适的阳极注入层基础。在OLED中使用高导电率级的，通常会导致常规OLED器件寿命变差。在本文使用的印刷掺杂的LEP器件结构(LEC-类型，根据基兹梅亚参考文献中的掺杂的LEP制剂),中，已经反复表明标准OLED级别的PEDOT:PSS如AI4083不会显著影响器件性能。这与下述事实是一致的：本文使用的掺杂的SY LEP器件预期受益于因为存在合适的电极/活性层功函匹配和来自活性层掺杂剂的有效掺杂而带来的空穴注入增加。Published in "J.Mater.Chem.", 2005,15,2077-2088, "Scientific importance, properties and growing applications of poly(3,4-ethylenedioxythiophene)" (referred to as "Kizmeya reference") A device of the formulation described was used to test these hypotheses, but also included an ionic liquid-doped PEDOT layer adjacent to the anode. A commercially available Clevios PEDOT:PSS formulation was chosen as a suitable base for the anode injection layer. The use of high conductivity grades in OLEDs generally results in poor lifetime of conventional OLED devices. In the printed doped LEP device structure used here (LEC-type, according to the doped LEP formulation in the Kizmeyer reference), it has been repeatedly shown that standard OLED grades of PEDOT:PSS such as AI4083 do not significantly affect device performance. This is consistent with the fact that the doped SY LEP devices used here are expected to benefit from hole injection due to the presence of a suitable electrode/active layer work function match and efficient doping from active layer dopants Increase.

在这些实施方式所描述的印刷器件结构中，我们期望高度导电的掺杂剂注入层能带来益处，我们看到了基于用离子液体丁基甲基吡咯烷三氟甲磺酸硫酰亚胺(BMPYRTfSi)掺杂的克里维斯（Clevios）PH500层的阳极掺杂剂注入层具有良好结果，该离子液体具有高度迁移的阳离子，表现为比参比的四烷基铵盐阳离子更快的器件动力学，且具有更低的结晶趋势。本文掺杂的阴极实验中使用的阳极堆叠件的电学性质见表3。如所预期的，ITO+PEDOT:PSS堆叠件的面电阻由更加高度导电的ITO主导。这里，PH500和PH100的电阻率值比文献报道的更高，可能是因为溶液过滤和热学制备的差异引起的。但是，在2者之间观察到了预期的电阻率趋势。我们观察到，对于大多数范围的掺杂的PH500/ITO堆叠件，因为存在导电的掺杂的PEDOT:PSS层，总体平行面电阻率有所下降。有趣的是，通过ITO+PEDOT:PSS可知，非常高度BMP-(丁基甲基吡咯烷三氟甲磺酸硫酰亚胺)掺杂的PH500最终下降，如样品ID#3的BMP堆叠件数据中，堆叠件的电阻率升高至与只有ITO的堆叠件的面电阻率大致相同(通过首诺科特玻璃功能膜公司（CPFilms）沉积的OC50ITO/Melinex ST504PET)。在这种情况下，掺杂剂含量约占该层“固体”总浓度的50％。这时，PEDOT载流子种类的有效导电率可能会因为稀释、孤岛形成或者过滤损失等而失效。在表3中，通过样品名称之前的“#x”来标示相对掺杂剂浓度，这是相对于AV-L1231Y配方中掺杂剂水平的掺杂剂水平倍数。例如，PH500_BMPX2的阳极层掺杂剂浓度是PH500_BMPX1的2倍。对于这些器件，参比掺杂剂水平占掺杂剂阳极层固体总量的4.3%。In the printed device structures described in these embodiments, we expect the benefit of a highly conductive dopant-implanted layer, we see based on the ionic liquid butylmethylpyrrolidine trifluoromethanesulfonate Good results for the anode dopant implantation layer of the doped Clevios PH500 layer with highly mobile cations exhibiting faster device kinetics than the reference tetraalkylammonium salt cations , and has a lower crystallization tendency. The electrical properties of the anode stacks used in the doped cathode experiments in this paper are shown in Table 3. As expected, the sheet resistance of the ITO+PEDOT:PSS stack is dominated by the more highly conductive ITO. Here, the resistivity values of PH500 and PH100 are higher than those reported in the literature, possibly due to differences in solution filtration and thermal preparation. However, the expected resistivity trend was observed between the two. We observed that for most ranges of doped PH500/ITO stacks, the overall parallel plane resistivity is reduced due to the presence of the conductive doped PEDOT:PSS layer. Interestingly, through ITO+PEDOT:PSS, it can be seen that the PH500 doped with very high BMP-(butylmethylpyrrolidine trifluoromethanesulfonate sulfimide) eventually drops, as in the BMP stack data ofsample ID#3, The resistivity of the stack was raised to approximately the same areal resistivity as the ITO-only stack (OC50ITO/Melinex ST504PET deposited by CPFilms). In this case, the dopant content is approximately 50% of the total concentration of "solids" in the layer. At this time, the effective conductivity of the PEDOT carrier species may be lost due to dilution, island formation, or filtration loss. In Table 3, the relative dopant concentration is indicated by "#x" before the sample name, which is the dopant level multiple relative to the dopant level in the AV-L1231Y formulation. For example, the anode layer dopant concentration of PH500_BMPX2 is twice that of PH500_BMPX1. For these devices, the reference dopant level was 4.3% of the total solids of the dopant anode layer.

表3在OC50ITO/PET上的、不同掺杂剂水平的PH500-基PEDOT膜的面电阻。Table 3 Sheet resistance of PH500-based PEDOT films at different dopant levels on OC50ITO/PET.

来自2实验的恒流下的器件寿命（到最高发光度一半的时间）和最大效率数据表明，当该阳极层中的离子液体浓度最高为参比层的4X，或～12重量%的额外掺杂剂，效率和寿命与离子液体浓度呈正向趋势。这些器件与前述的掺杂的阴极器件的建造和制剂类似，但该阴极是未掺杂的（与10-243-1阴极制剂类似）且引入了阳极层。Device lifetime (time to half maximum luminosity) and maximum efficiency data at constant current from 2 experiments show that when the ionic liquid concentration in the anode layer is up to 4X that of the reference layer, or ~12 wt% additional doping agent, the efficiency and lifetime showed a positive trend with the ionic liquid concentration. These devices were constructed and formulated similarly to the previously described doped cathode devices, but the cathode was undoped (similar to the 10-243-1 cathode formulation) and an anodic layer was incorporated.

还进行了其它实验，其中器件具有阳极掺杂剂注入层，且掺杂剂浓度范围更宽，为从x2到x16。这些实验的数据见表4。这些数据表明最高掺杂水平的性能下降。包含更低迁移率阳离子的混合掺杂剂的性能更差，表明阳离子扩散系数很可能是重要的。Other experiments were also performed in which devices had an anode dopant injection layer and a wider range of dopant concentrations from x2 to x16. The data for these experiments are presented in Table 4. These data show a drop in performance for the highest doping levels. Mixed dopants containing lower mobility cations performed worse, suggesting that the cation diffusion coefficient is likely to be important.

图3显示了图表结果，组合了多个实验数据组，且每一组都相对于它们的对照标准化。器件发光度寿命对掺杂水平的二阶指数拟合表明，最佳掺杂水平为占导电阳极总重量的～17%。本领域技术人员应理解，虽然本文使用了指数拟合，也可使用其它的数学拟合机理。Figure 3 shows the results graphically, combining multiple experimental data sets, each normalized to their controls. A second-order exponential fit of the device luminance lifetime to the doping level indicated that the optimal doping level was ~17% of the total weight of the conducting anode. It will be appreciated by those skilled in the art that although exponential fitting is used herein, other mathematical fitting mechanisms may be used.

表4具有掺杂的导电阳极层的印刷掺杂的OLED所得的最高产率实验数据组。Table 4 Highest yield experimental data set from printing doped OLEDs with doped conductive anode layer.

*“MIX”指该器件用由BMPYRTfSI/TBATfSi混合物掺杂的PEDOT:PSS掺杂剂注入层制造而成，与‘BMP’-表示只有BMPYRTfSi掺杂剂的样品相对*"MIX" means the device was fabricated with a PEDOT:PSS dopant implanted layer doped with a BMPYRTfSI/TBATfSi mixture, as opposed to 'BMP' - meaning only the BMPYRTfSi dopant sample

图4A-4C显示了具有印刷电极的“典型”单一LEP墨水组合物PLED在器件寿命的离子掺杂情况，起始于左边（刚制备的，未偏压），中间（应用偏压后的初始情况），右边（初始开启之后的阶段－在典型情况下数十小时），其中用专门的材料掺杂PLED，例如可从总部位于加利福尼亚州斯科茨谷的、以前称为阿德威津公司（Add-Vision,Inc.，AVI）购买的组合物。假定初始时，阴离子和阳离子呈电中性的半均匀分布，在阴极的沉积和加工中（图4A），可能有些电解质会浸渍进入阴极。在偏压下的离子运动，将阳离子移动到阴极，且将阴离子移动到阳极。随着离子辅助的从该电极进入LEP的隧穿率上升，形成电荷注入（图4B）。随着离子漂移的持续，在该器件内部的离子浓度下降，这可增加辐射效率。Figures 4A-4C show the ion doping profile over the lifetime of the device for a "typical" single LEP ink composition PLED with printed electrodes, starting on the left (as-fabricated, unbiased), middle (initial after bias application). case), on the right (the stage after initial turn-on—typically tens of hours), in which PLEDs are doped with specialized materials such as those available from Scotts Valley, Calif. (Add-Vision, Inc., AVI). Assuming an initial, electrically neutral, semi-uniform distribution of anions and cations, some electrolyte may impregnate into the cathode during deposition and processing of the cathode (Fig. 4A). Ion movement under bias moves cations to the cathode and anions to the anode. Charge injection occurs as the ion-assisted tunneling rate from this electrode into the LEP increases (Fig. 4B). As ion drift continues, the concentration of ions inside the device decreases, which increases radiation efficiency.

图5A-5C显示了掺杂的多活性层器件在偏压下的离子发展，其中例如通过印刷在该器件的后续活性层中引入不同的掺杂水平。这个技术可导致在该器件偏压的早期，与均匀掺杂的器件（如图4A-4C所示）相比，接近阴极处具有相对高的阳离子浓度。这对于均匀掺杂的阴极注入受限器件具有一些优越性。但是，这种器件构造受限于下述事实：在该器件中的阴离子和阳离子的浓度是相等的，这对固有的通过电子和空穴注入平衡的典型器件来说，不是优化的。这还导致在该器件的活性半导体层中，抗衡离子浓度不必要的高于优化浓度，这会导致淬灭、过度掺杂和性能降低。Figures 5A-5C show the ion development under bias of a doped multiple active layer device where different doping levels are introduced in subsequent active layers of the device, for example by printing. This technique results in a relatively high cation concentration near the cathode early in the biasing of the device compared to a uniformly doped device (as shown in Figures 4A-4C). This has some advantages for uniformly doped cathode injection-limited devices. However, this device configuration is limited by the fact that the concentrations of anions and cations in the device are equal, which is not optimal for typical devices inherently balanced by electron and hole injection. It also leads to unnecessarily higher than optimal concentrations of counterions in the active semiconductor layer of the device, which can lead to quenching, overdoping and reduced performance.

注意到现有LEP多层结构（例如LEP/+空穴注入层结构）与本发明的掺杂剂注入层有显著差异，具体在于本发明的实施方式中的供电子层是明显导电的。如上所述，掺杂剂注入层是导电的是非常重要的，因为金属导体在该层的本体中（在包括导电聚合物的有限载流子浓度的金属中，有可能存在一些薄区域的非零电场）具有基本上为零电场，且能在具体的偏压下维持。这可用于将阳离子或阴离子固定在该层（在阳离子注入掺杂剂供体层的情况下是阴离子），同时将抗衡离子驱动进入邻近的活性层。注意到这种固定不依赖于结构引起的离子迁移率。由电场固定的导电（阴离子，在这个掺杂阳极层的离子中）离子的位置，在器件寿命中是相对恒定的，这与具有有限电场的非导体不同，该有限电场趋于随着寿命驱使在阳极界面形成高浓度，这可能是因过多掺杂和屏蔽效应产生的退化和电压升高的额外来源。在导电的情况下，离子从该器件的活性层驱动进入离子支撑供体层且变成固定的，并因此具有有限的影响，可能会致使金属供体层中已经高的载流子浓度有少量增加。与图4A-4B所示的均匀掺杂的器件相比，这些类型的器件常常导致更早开始电子注入和更高的电子注入和更高的电子/空穴比例。It is noted that existing LEP multilayer structures (such as LEP/+hole injection layer structures) differ significantly from the dopant injection layer of the present invention, in particular that the electron donating layer in embodiments of the present invention is significantly conductive. As mentioned above, it is very important that the dopant-injection layer is conductive, since the metal conductor is in the bulk of the layer (in metals of finite carrier concentration including conductive polymers, there may be some thin regions of non-conductive zero electric field) has a substantially zero electric field that can be maintained at a specified bias voltage. This can be used to anchor cations or anions to the layer (anions in the case of cation-implanted dopant-donor layers), while driving counterions into the adjacent active layer. Note that this immobilization does not depend on structure-induced ion mobility. The position of the conducting (anions, in this ion doping the anode layer) ions, fixed by the electric field, is relatively constant over the lifetime of the device, unlike non-conductors which have a finite electric field which tends to drive High concentrations form at the anode interface, which may be an additional source of degradation and voltage rise due to overdoping and screening effects. In the case of conduction, ions are driven from the active layer of the device into the ion-supporting donor layer and become immobilized, and thus have limited influence, possibly causing a small amount of loss of the already high carrier concentration in the metal donor layer. Increase. These types of devices often result in earlier onset of electron injection and higher electron injection and higher electron/hole ratios than the uniformly doped devices shown in Figures 4A-4B.

图6A-6C显示了有掺杂的阴极和均匀LEP墨水组合物制成的器件随器件寿命的离子掺杂情况。左边的图6A显示刚制成的未偏压的器件；中部的图6A显示应用偏压后的初始情况；以及右边的图6C显示在初始开启阶段后的情况，例如在典型情况下数十小时之后。在该阴极中的零电场，和在正向偏压情况下设置在该阴极的负偏压，本身将阳离子固定在该阴极中并优先的注入阴离子。在正向偏压的稳定状态情况下，在该器件的活性层将具有更高的净阴离子浓度，这在去除偏压后会释放。具体来说，图6B显示在器件中可观察相对于未掺杂的阴极的高的阴离子浓度。阳离子趋于保留在负向偏压的阴极中。因为阴极的低扩散系数和大的供应体积（更厚的阴极），图6C表明阴离子将持续的从阴极漂移。因为增强的空穴注入，高的阴离子浓度可将电子/空穴平衡进一步偏向空穴主导。Figures 6A-6C show ion doping over device lifetime for devices made with doped cathodes and uniform LEP ink compositions. Figure 6A on the left shows an as-fabricated unbiased device; Figure 6A in the middle shows the initial situation after application of a bias voltage; and Figure 6C on the right shows the situation after the initial turn-on phase, such as typically tens of hours after. A zero electric field in the cathode, and in the case of a forward bias, a negative bias on the cathode itself fixes cations in the cathode and preferentially injects anions. In the steady state condition of forward bias, the active layer of the device will have a higher net anion concentration, which is released after the bias is removed. In particular, Figure 6B shows that a high anion concentration can be observed in the device relative to the undoped cathode. Cations tend to remain in a negatively biased cathode. Because of the low diffusion coefficient of the cathode and the large supply volume (thicker cathode), Figure 6C shows that anions will continue to drift away from the cathode. A high anion concentration can shift the electron/hole balance further towards hole dominance because of enhanced hole injection.

图7A-7C显示了有掺杂的阳极层和有印刷阴极的、“典型”单一LEP墨水组合物AVI掺杂的PLED制成的器件随器件寿命的离子掺杂情况。左边的图7A显示刚制成的未偏压的器件；中部的图7A显示应用偏压后的初始情况；以及右边的图7C显示在初始开启阶段后的情况，例如在典型情况下数十小时之后。还可设想提高阴极/阳离子掺杂效率的可行途径是包括掺杂的阳极。这与在非-LEC、未掺杂的常规OLED/PLED中使用的PEDOT不同，在常规OLED中，从阴极到活性区域的自由离子运动是不利的，且被故意抑制。具体来说，因为阴极的低扩散系数和大的供应体积（更厚的阴极），图7C表明阴离子将持续的从阴极漂移。因为增强的空穴注入，高的阴离子浓度可将电子/空穴平衡进一步偏向空穴主导。LEP中稳定状态下的阳离子浓度高于阴离子浓度。Figures 7A-7C show the ion doping profile over device lifetime for devices made from "typical" single LEP ink composition AVI-doped PLEDs with doped anode layers and printed cathodes. Figure 7A on the left shows an as-fabricated unbiased device; Figure 7A in the middle shows the initial situation after application of a bias voltage; and Figure 7C on the right shows the situation after the initial turn-on phase, such as typically tens of hours after. It is also conceivable that a feasible way to increase the efficiency of cathode/cation doping is to include doped anodes. This differs from PEDOT used in non-LEC, undoped conventional OLEDs/PLEDs, where the movement of free ions from the cathode to the active region is unfavorable and intentionally suppressed. Specifically, because of the low diffusion coefficient of the cathode and the large supply volume (thicker cathode), Figure 7C indicates that anions will continue to drift away from the cathode. A high anion concentration can shift the electron/hole balance further towards hole dominance because of enhanced hole injection. The concentration of cations at steady state in LEP is higher than that of anions.

本发明的其它可能的实施方式包括通过导电特征形成的金属性或半金属性掺杂剂注入层，例如Ag纳米线网、导电纳米管网或特意图案化的导体网。该注入复合材料的额外组分可以是离子支撑材料和/或电解质形成剂，可用作离子来源且还可具有平面化能力。这种复合材料可用作阳极或阴极掺杂剂注入层，且可具有下述益处：透明的（需要时）、柔性的、且潜在的消除了更昂贵或更难的沉积层（如铟锡氧化物）的需求。Other possible embodiments of the invention include metallic or semi-metallic dopant implanted layers formed by conductive features, such as Ag nanowire meshes, conductive nanotube meshes, or deliberately patterned conductor meshes. Additional components of the infused composite may be ion-supporting materials and/or electrolyte formers, which may serve as a source of ions and may also have planarizing capabilities. This composite material can be used as an anode or cathode dopant injection layer, and can have the following benefits: transparent (where required), flexible, and potentially eliminates more expensive or difficult to deposit layers (such as indium tin oxides) requirements.

尽管本发明出于举例说明的目的描述了某些特定的代表性实施方式和详细描述，但是对于本领域技术人员来说很明显的是，可以对本文所述的方法和设备进行各种改变，同时不偏离所附权利要求书所揭示的本发明的范围。此外，本说明书中提到的材料的商业名称只用于帮助读者的理解，而没有暗示本发明只受限于某些器件构造和本文提到的材料。While certain specific representative embodiments and detailed description have been described for purposes of illustration, it will be apparent to those skilled in the art that various changes can be made in the methods and apparatus described herein, without departing from the scope of the present invention as disclosed in the appended claims. In addition, the trade names of materials mentioned in this specification are only used to aid the reader's understanding, and do not imply that the present invention is limited to only certain device configurations and materials mentioned herein.

Claims (8)

Translated fromChinese

1.用于电子器件的等电位源层，其特征在于，所述等电位源层提供优先注入该电子器件的活性层的带电荷离子，其中这种被注入的离子的电荷具有与施加到该等电位源层的相对偏压的符号相同的符号。1. An equipotential source layer for an electronic device, characterized in that the equipotential source layer provides charged ions that are preferentially injected into the active layer of the electronic device, wherein the charges of such implanted ions have the same characteristics as those applied to the The signs of the relative bias voltages of the equipotential source layers are the same.2.一种包含如权利要求1所述的等电位源层的电子器件，其特征在于，所述等电位源层包括复合材料离子掺杂剂注入层，该复合材料离子掺杂剂注入层包括至少一种对离子具有相对高的扩散系数的组分。2. An electronic device comprising an equipotential source layer as claimed in claim 1, wherein the equipotential source layer comprises a composite material ion dopant implantation layer, and the composite material ion dopant implantation layer comprises At least one component having a relatively high diffusion coefficient for ions.3.如权利要求2所述的器件，其特征在于，所述复合材料离子掺杂剂注入层包括金属性导电颗粒和离子支撑基质。3. The device according to claim 2, wherein the composite ion dopant implantation layer comprises metallic conductive particles and an ion-supporting matrix.4.如权利要求2所述的器件，其特征在于，所述复合材料离子掺杂剂注入层包括连续的金属性导电网络和离子支撑基质。4. The device of claim 2, wherein the composite ion dopant implanted layer comprises a continuous metallic conductive network and an ion-supporting matrix.5.如权利要求4所述的器件，其特征在于，所述金属性导电网络包括金属性纳米线或者导电纳米管。5. The device according to claim 4, wherein the metallic conductive network comprises metallic nanowires or conductive nanotubes.6.如权利要求3或4所述的器件，其特征在于，所述离子支撑基质包括导电聚合物。6. The device of claim 3 or 4, wherein the ionically supporting matrix comprises a conductive polymer.7.如权利要求2-6任一项所述的器件，其特征在于，所述器件包括透明阳极、与该透明阳极接触的导电聚合物层，以及邻近所述活性层的额外的可移动的离子掺杂剂。7. The device of any one of claims 2-6, comprising a transparent anode, a conductive polymer layer in contact with the transparent anode, and an additional removable ion dopants.8.如权利要求2-7任一项所述的器件，其特征在于，所述器件包括透明阴极和掺杂的阳极，所述掺杂的阳极是金属性元件的连续导电网络和离子支撑基质形成的复合材料。8. A device according to any one of claims 2-7, characterized in that it comprises a transparent cathode and a doped anode which is a continuous conductive network of metallic elements and an ion-supporting matrix formed composite material.

Images